Plant Evolution & Diversity

Question 1

What are the primary differences between algae and land plants?

Answer 1

algae have primitive features;

land plants have derived features

Question 2

What are the primitive features of algae?

Answer 2

thalus (body) & holdfast

Question 3

What are the derived features of land plants?

Answer 3

leaves, stems, roots

Question 4

What were the ancestors of land plants?

Answer 4

Charophytes (green algae)

Question 5

What is the habitat of charophytes?

Answer 5

freshwater

Question 6

What are the shared biochemical features of land plants and their ancestors (charophytes)?

Answer 6

enxymes that make cellulose,

peroxisomes (organelles that contain enzymes)

Question 7

What are the specialized parts (“organs”) of plants that help to maintain water balance?

Answer 7

stomata & waxy cuticle covering

Question 8

What are the specialized parts (‘organs’) of plants that help to obtain resources and what resources do they obtain?

Answer 8

shoots (solar energy & CO2),

roots (water & dissolved nutrients)

Question 9

What were mycorrhizae crucial in?

Answer 9

the ability of plants to inhabit dry land

Question 10

What are mycorrhizae and what do they do?

Answer 10

intimate mutualistic associations of plant roots and fungal hyphae;
increase the absorption of minearls and water

Question 11

What does primary growth in plants accomplish?

Answer 11

extends the length of a plant both aboveground (shoot system) and belowground (root system)

Question 12

What produces the new cells for the primary growth of the shoot system?

Answer 12

shoot apical meristem

Question 13

What produces the new cells for the primary growth of the root system?

Answer 13

root apical merastem

Question 14

What is secondary growth?

Answer 14

growth in the lateral direction (stems thicken)

Question 15

What is the function of secondary growth in plants?

Answer 15

strength (support weight),

get leaves closer to sun

Question 16

In secondary growth, what produces the new cells?

Answer 16

vascular combium (tissue just under the bark)

Question 17

What is the outgroup in the land plant clade?

Answer 17

charophytes (group of green algae)

Question 18

What was the order of divergence of land plants, from first to last?

Answer 18

1) bryophytes (e.g. mosses)
2) seedless vascular plants (e.g. ferns, horsetails)
3) gymnosperms (e.g. conifers, cycads)
4) angiosperms (flowering plants)

Question 19

What some early vascular plants?

Answer 19

ferns, horsetails

Question 20

What were the first seed plants?

Answer 20

gymnosperms (e.g. conifers, cycads)

Question 21

What is the name for flowering plants?

Answer 21

angiosperms

Question 22

What is the life cycle for the basic scheme of alteration of generations, starting at fertilization?

Answer 22

1) fertilization –> 2N zygote
2) mitosis –> 2N sporophyte
3) growth and mitosis
4) meiosis –> spores (N)
5) mitosis –> N gametophyte (haploid)
6) mitosis –> gametes (N)

Question 23

Why are bryophytes small (few cms)?

Answer 23

they lack vascular tissues

Question 24

What are the green plant bodies of mosses?

Answer 24

gametophytes (?)

Question 25

What is the life cycle of a typical moss, starging with sperm?

Answer 25

1) sperm (n) released from their gametangium (gametangium containing n egg remains within gametopphyte)
2) fertilization –> zygote (2n)
3) mitosis and development –> sporophytes growing from gametophytes (n)
4) mitosis –> spore (n)
5) mitosis and development –> gametophytes (n)
6) sperm released from gametangium

Question 26

What do ferns produce?

Answer 26

spores (NOT seeds)

Question 27

Are fern plants haploid or diploid?

Answer 27

diploid

Question 28

What are some other seedless vascular plants (“fern allies”)?

Answer 28

ground pine (Lycopodium), horsetails (Equisetum)

Question 29

What are sporophylls?

Answer 29

leaves specialized for reproduction

Question 30

Where are the repdocutive structures of ferns found?

Answer 30

on the undersides of mature leaves

Question 31

How small are fern gametophytes and new sporophytes?

Answer 31

tiny (<1 cm)

Question 32

What is a sorus?

Answer 32

a cluster of sporangia (structures producing and containing spores)

Question 33

What is the life cycle of a fern, starting with fertilization?

Answer 33

1) fertilization –> zygote
2) growth… –> gametophyte + baby sporophyte
3) long-lived sporophyte (2N)
4) sori… meiosis
5) short-lived but free-living gametophyte (N)

Question 34

In what plants is protection for reproduction found?

Answer 34

seed plants

Question 35

What is the sperm protected inside in seed plants?

Answer 35

the pollen grain

Question 36

Where does the pollen tube grow out of and why?

Answer 36

pollen tube grows out of pollen grain;

to bring the sperm to the egg